JP2001199024A - Multilayered container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayered container using polyamide MXD6, holding transparency without being whitened and crystallized even if polyamide MXD6 is present in a part lower in draw ratio and having good appearance and good gas barrier properties. SOLUTION: In the multilayered container wherein a resin constituting outermost and innermost layers is a thermoplastic polyester resin (resin A) and a resin constituting at least one intermediate layer between the outermost and innermost layers is a thermoplastic gas barrier resin (resin B), the thermoplastic gas barrier resin (resin B) is obtained by adding 0.005-1.0 parts by weight of an additive (whitening inhibitor) having the whitening preventing function of polyamide to 100 parts by weight of polyamide obtained by the melt polymerization of a diamine component containing 70 mol% or more of metaxylenediamine and a dicarboxylic acid component containing 70 mol% or more of adipic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a thermoplastic gas barrier resin (for example, metaxylene) constituting an intermediate layer even when a hollow container having a multilayer structure (for example, a biaxially stretched blow molded multilayer container) is stored for a long period of time. A polyamide obtained by polymerizing a diamine and adipic acid (hereinafter referred to as "polyamide M
XD6 ")), which keeps the whitening increase low,
The present invention relates to a multilayer container having excellent gas barrier properties, wherein transparency is maintained for a long time.

[0002]

2. Description of the Related Art The demand for plastic containers has been increasing year by year as plastic beverage containers have become more plastic, and the demand for small containers has become particularly large. On the other hand, as the size of the container is reduced, the ratio of the surface area per unit volume of the container increases. When the size of the container is reduced, the expiration date of the contents is shorter than that of the conventional large container. Therefore, it is necessary to improve the gas barrier property of the container only by maintaining the expiration date of the conventional large container. In recent years, plasticization of beer containers has been studied and put on the market, but the required performance for gas barrier properties of beer containers is generally higher than that of soft drinks.

A multilayer container made of a polyester resin and a polyamide MXD6 is widely used as a plastic container satisfying the above-mentioned required performance due to the good gas barrier property and the fragrance retention property of the polyamide MXD6.

However, when the polyamide MXD6 is in an amorphous, non-stretched or amorphous, low-magnification stretched state, it may be heated at a temperature higher than the glass transition temperature, stored under high humidity, or contacted with water or boiling water. It has the property of being whitened and crystallized to lower transparency. For this reason, there is a restriction on use in a high humidity atmosphere or use in a state of contact with water. In particular, polyamide M which is further solid-phase polymerized after melt polymerization for use in containers, films and sheets
Since XD6 has a low crystallization speed, it is easy to whiten and crystallize, and in the case of a multilayer container, there is a problem that the appearance of polyamide MXD6 having an amorphous and low stretch ratio in the intermediate layer is significantly impaired.

[0005] As a method of avoiding such a problem, in a multilayer container, polyamide MXD6 is applied to a portion where the stretching ratio is secured to 2.5 times or more in any one direction so that the intermediate layer is not whitened or crystallized. It has been forced to adjust its position to exist.

In general, a hollow multilayer container is obtained by biaxially stretch-blow-molding a parison, which is a precursor thereof. When a biaxially stretched blow-molded multilayer container is obtained from a parison, the stretching ratio of the multilayer container is the same as that of the parison. Due to the shape of the container, the stretching ratio generally increases from the low stretching ratio portions of the neck and shoulder to the trunk portion through the non-stretching portion of the plug portion. Further, the stretching ratio of the multilayer container can be roughly calculated from the dimensions of the parison and the biaxially stretch blow-molded multilayer container. Therefore, the polyamide M constituting the intermediate layer of the multilayer container
The polyamide MXD6 is whitened and crystallized by adjusting the location of the XD6 so that the polyamide MXD6 is located at the shoulder or the trunk where the stretching ratio is 2.5 times or more in any one direction from the resin injection port. A multi-layer container is produced without any problems. In addition, the adjustment of the tip position where the polyamide MXD6 exists,
In the production of a multilayer parison, which is a precursor thereof, it can be easily controlled by controlling the timing of injecting the polyester resin and the polyamide MXD6.
In a multilayer container, the polyamide MX
D6 whitening has been avoided.

However, in a multilayer container, when the position of the polyamide MXD 6 layer extends only to the shoulder or the trunk, the portion preceding the portion becomes a polyester resin single-layer structure. The gas barrier property is considerably reduced as compared with the case where the position of the polyamide MXD6 layer extends to the plug portion via the plug. Therefore, not only can the required gas barrier properties not be achieved, but it is necessary to increase the amount of polyamide MXD6 resin used to achieve the same performance.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art, and to provide a multilayer container using polyamide MXD6.
When D6 is present in a portion where the stretching ratio is low, that is,
An object of the present invention is to provide a multilayer container having good appearance and good gas barrier properties, which is transparent without being whitened or crystallized even when it extends to the plug portion of the multilayer container.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies to prevent the whitening and crystallization of the thermoplastic gas barrier resin constituting the intermediate layer of the multilayer container and to obtain a multilayer container having a good appearance. As a result of stacking, amorphous and non-stretched or amorphous and low-magnification stretched state by adding additives to polyamide which is a thermoplastic gas barrier resin, when heated above the glass transition temperature, under high humidity The present inventors have found that a multi-layered container which can maintain transparency without being whitened or crystallized during the storage of water or in contact with water or boiling water has been completed, and the present invention has been completed.

That is, according to the present invention, the resin constituting the outermost layer and the innermost layer is a thermoplastic polyester resin (resin A).
Wherein at least one intermediate layer between the outermost layer and the innermost layer is a multilayer container made of a thermoplastic gas barrier resin (resin B), wherein the thermoplastic gas barrier resin (resin B) contains meta-xylylenediamine. 0.005 parts by mass of a polyamide obtained by melt-polymerizing a diamine component containing at least 70 mol% and a dicarboxylic acid component containing at least 70 mol% of adipic acid with 0.005 to 5 wt.
The invention relates to a multilayer container characterized by being a resin obtained by adding 1.0 part by mass.

The multilayer container of the present invention can be molded by, for example, a usual injection molding method, but can also be obtained by biaxially stretch blow molding a multilayer parison which is a container precursor. The multilayer parison is obtained by injecting the thermoplastic polyester resin and the polyamide MXD6 from the respective injection cylinders through the mold hot runner and into the mold cavity.

In the method for producing a multilayer parison according to the above-mentioned method, first, a thermoplastic polyester resin is injected, and then a polyamide MXD6 is injected simultaneously with the thermoplastic polyester resin to fill the cavity, thereby forming a parison having a three-layer structure. Can be manufactured. According to such a manufacturing method, the resin constituting the outermost layer and the innermost layer comprises a thermoplastic polyester resin (resin A), and the resin constituting the intermediate layer located between the outermost layer and the innermost layer comprises a thermoplastic gas barrier resin. A three-layer container made of (resin B),
And a thermoplastic gas barrier resin (resin B) constituting an intermediate layer is disposed from the resin injection port located at the bottom of the container to the vicinity of a plug opposite to the injection port. Obtainable.

Similarly, in a method for manufacturing a parison by injecting a thermoplastic polyester resin and a polyamide MXD6 into a mold cavity, first inject the thermoplastic polyester resin, then inject the polyamide MXD6 alone, A parison having a five-layer structure can be manufactured by injecting a thermoplastic polyester resin into the cavity. The method for producing the multilayer parison is not limited to the above method. According to this method, the resin constituting the outermost layer, the innermost layer and the central layer is made of a thermoplastic polyester resin (resin A), and the resin constituting the outermost layer and the central layer and the intermediate layer located between the innermost layer and the central layer. Is a five-layer container made of a thermoplastic gas barrier resin (resin B), and the thermoplastic gas barrier resin (resin B) forming the intermediate layer is filled from the resin inlet side located at the bottom of the container. A multi-layer container characterized by being a five-layer container arranged to the vicinity of the plug portion facing the side can be obtained.

In a multilayer parison or a multilayer container obtained by biaxially stretch-blow molding a multilayer parison, the gas barrier performance of the container is preferably such that the gas barrier layer as the intermediate layer extends to the vicinity of the plug. It is.

In the present invention, the thermoplastic polyester resin (resin A) is usually terephthalic acid in an amount of at least 80 mol%, preferably at least 90 mol% of the acid component, and at least 80 mol%, preferably at least 90 mol% of the glycol component. % Or more of ethylene glycol, and the remaining other acid components are isophthalic acid, diphenyl ether-4, 4-dicarboxylic acid, naphthalene-1, 4, or 2,
6-dicarboxylic acid, adipic acid, sebacic acid, decane
1,10-carboxylic acid, hexahydroterephthalic acid,
Other glycol components include propylene glycol,
1,4-butanediol, neopentyl glycol, diethylene glycol, cyclohexanedimethanol,
2,2-bis (4-hydroxyphenyl) propane,
2,2-bis (4-hydroxyethoxyfur) propane and the like can be exemplified. Further, P as an oxyacid
-A polyester resin containing oxybenzoic acid or the like can also be exemplified.

The intrinsic viscosity of these thermoplastic polyester resins is suitably at least 0.55, preferably at least 0.65.
~ 1.4. When the intrinsic viscosity is less than 0.55, it is difficult to obtain a multilayer parison in a transparent amorphous state,
The mechanical strength of the resulting hollow container is also insufficient. In the present invention, the combination of thermoplastic polyester resin, especially polyethylene terephthalate and polyamide MXD6 is most preferable because of excellent transparency, mechanical strength, injection moldability and stretch blow moldability of the resin. Because it is.

In the present invention, if necessary, a colorant, an ultraviolet absorber, an antistatic agent, an antioxidant, a lubricant, a nucleating agent, an antibacterial agent and the like may be added to one or more of the resins. Can be done.

The polyamide (hereinafter sometimes referred to as "polyamide") as a main component of the thermoplastic gas barrier resin (resin B) used in the present invention is obtained by melt-polymerizing the following diamine component and dicarboxylic acid component. Is used.
Metaxylylenediamine is 70 mol% in the diamine component
It is necessary to include the above. When the amount of meta-xylylenediamine in the diamine component is 70% or more, excellent gas barrier properties can be maintained.

Other diamines that can be used besides meta-xylylenediamine include paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, tetramethylenediamine, hexamethylenediamine, nona Methylene diamine,
Examples thereof include 2-methyl-1,5-pentanediamine, but are not limited thereto.

In the dicarboxylic acid component, adipic acid contains 7
It must be contained at 0 mol% or more. When the amount of adipic acid in the dicarboxylic acid component is 70 mol% or more, a decrease in gas barrier properties and a decrease in crystallinity can be avoided. Examples of dicarboxylic acid components that can be used other than adipic acid include suberic acid, azelaic acid, sebacic acid, 1,10-decanedicarboxylic acid, terephthalic acid, isophthalic acid, 2,6
-Naphthalenedicarboxylic acid and the like, but are not limited thereto. Further, a small amount of a monoamine or a monocarboxylic acid may be added as a molecular weight regulator during the polycondensation of the polyamide.

The above polyamide is produced by a melt polycondensation method. For example, it is produced by a method in which a nylon salt composed of meta-xylylenediamine and adipic acid is heated in the presence of water under pressure and polymerized in a molten state while removing added water and condensed water. Further, it is also produced by a method in which meta-xylylenediamine is directly added to adipic acid in a molten state and polycondensed under normal pressure. In this case, in order to keep the reaction system in a uniform liquid state, meta-xylylenediamine is continuously added to adipic acid, and during this time, the reaction system is raised so that the reaction temperature does not fall below the melting points of the resulting oligoamide and polyamide. While heating, the polycondensation proceeds.

The relative viscosity of polyamide having a relatively low molecular weight obtained by melt polymerization (1 g of polyamide resin dissolved in 100 ml of a 96% aqueous sulfuric acid solution and measured at 25 ° C., the same applies hereinafter) is usually about 2.28. . When the relative viscosity after the melt polymerization is 2.28 or less, a high-quality polyamide having a low color tone and a good color tone can be obtained. It is desirable that the relatively low molecular weight polyamide obtained by melt polymerization is further subjected to solid phase polymerization. Solid-state polymerization is performed by heating a relatively low-molecular-weight polyamide obtained by melt polymerization into pellets or powder and heating it at a temperature ranging from 150 ° C. to the melting point of the polyamide under reduced pressure or an inert gas atmosphere. Will be implemented. The relative viscosity of the solid-phase polymerized polyamide is desirably 2.3 to 4.2. Within this range, the container, film, and sheet can be molded well, and the resulting container, film, and sheet can have good performance, particularly good mechanical performance. Some effects of the present invention can be obtained even with a polyamide having a relatively low molecular weight after melt polymerization, but the mechanical strength, particularly the impact resistance, is insufficient, and is not practical as a material for containers, films and sheets.

In the present invention, at least one compound selected from fatty acid metal salts is added to the polyamide used in the present invention as an additive having an anti-whitening function (anti-whitening agent). The fatty acid metal salt is a fatty acid metal salt having 18 to 50 carbon atoms, preferably 18 to 34 carbon atoms. Prevention of whitening can be expected when the number of carbon atoms is 18 or more. Further, when the carbon number is 50 or less, the uniform dispersion in the resin composition becomes good. Fatty acids may have side chains or double bonds, but may be stearic acid (C18), eicoic acid (C20), behenic acid (C2
2), montanic acid (C28), triacontanic acid (C3
Linear saturated fatty acids such as 0) are preferred. There are no particular restrictions on the metals that form salts with fatty acids, but sodium, potassium, lithium, calcium, barium, magnesium,
Strontium, aluminum, zinc and the like can be exemplified, among these, sodium, potassium, and lithium,
Calcium, aluminum and zinc are particularly preferred.

The above-mentioned fatty acid metal salts may be used alone or in combination of two or more. However, sodium stearate, calcium stearate, sodium montanate, calcium montanate are preferred as those having a good whitening prevention effect. Among them, sodium montanate and calcium montanate are particularly effective in preventing whitening. In the present invention, the shape of the fatty acid metal salt is not particularly limited, but the smaller the particle size is, the easier it is to disperse uniformly in the resin composition. Therefore, the particle size is preferably 0.2 mm or less.

In the present invention, the amount of the fatty acid metal salt to be added is 0.005 to 1.
0 parts by mass, preferably 0.05 to 0.5 parts by mass, particularly preferably 0.12 to 0.5 parts by mass. Polyamide 1
By adding 0.005 parts by mass or more to 00 parts by mass, an anti-whitening effect can be expected. When the amount is 1.0 part by mass or less with respect to 100 parts by mass of the polyamide, the haze value of a molded product obtained by molding the resin composition can be kept low.

In the present invention, at least one compound selected from a specific diamide compound and a diester compound may be added to the polyamide of the present invention as a whitening inhibitor.

The diamide compound used as the whitening inhibitor is a diamide compound obtained from a fatty acid having 8 to 30 carbon atoms and a diamine having 2 to 10 carbon atoms. When the fatty acid has 8 or more carbon atoms and the diamine has 2 or more carbon atoms, a whitening preventing effect can be expected. When the carbon number of the fatty acid is 30 or less and the carbon number of the diamine is 10 or less, uniform dispersion in the composition becomes good. Fatty acids may have side chains or double bonds,
Straight-chain saturated fatty acids are preferred. Preferably 8 to 3 carbon atoms
A diamide compound obtained from a fatty acid having 0 and a diamine mainly comprising ethylenediamine or a diamide compound obtained from a fatty acid mainly comprising montanic acid and a diamine having 2 to 10 carbon atoms.

As the fatty acid component of the diamide compound used in the present invention, stearic acid (C18) and eicoic acid (C
20), behenic acid (C22), montanic acid (C28),
Triacontanic acid (C30) can be exemplified. Examples of the diamine component of the diamide compound used in the present invention include ethylenediamine, butylenediamine, hexanediamine, xylylenediamine, bis (aminomethyl) cyclohexane, and the like. A diamide compound obtained by combining these is used in the present invention. The diamide compound is 1
Types or two or more types may be used in combination. Particularly preferred is a diamide compound obtained from a diamine mainly comprising ethylenediamine.

As the fatty acid component of the diester compound used in the present invention, stearic acid (C18), eicoic acid (C20), behenic acid (C22), montanic acid (C2
8) and triacontanic acid (C30). Examples of the diol component of the diester compound used in the present invention include ethylene glycol, propanediol, butanediol, hexanediol, xylylene glycol, and cyclohexanedimethanol. A diester compound obtained by combining these is used in the present invention. One type of diester compound may be used, or two or more types may be used in combination. Among them, particularly preferred are diester compounds obtained mainly from fatty acids mainly composed of montanic acid and ethylene glycol and / or 1,3-butanediol.

Examples of the diamide compound and diester compound used in the present invention include a copolymer of ethylenediamine and stearic acid, and a copolymer of ethylenediamine, stearic acid and sebacic acid. In particular, a copolymer of ethylenediamine and stearic acid is one having a whitening preventing effect. The diamide compound and the diester compound used in the present invention may be used alone or in combination.

In the present invention, the diamide compound and / or
Alternatively, the amount of the diester compound added is polyamide 100
0.005 to 1.0 part by mass, preferably 0.05 to 0.5 part by mass, particularly preferably 0.12 to 2 parts by mass,
0.5 parts by mass. By adding 0.005 parts by mass or more to 100 parts by mass of the polyamide, an effect of preventing whitening can be expected. When the addition amount is 1.0 part by mass or less based on 100 parts by mass of the polyamide, it is possible to keep the molded product obtained by molding the resin composition of the present invention at a low haze.

The thermoplastic gas barrier resin (resin B) of the present invention is not limited to other resins, specifically, other resins such as nylon 6 and nylon 66, as long as the object of the present invention, that is, transparency is not impaired. Saturated polyesters such as polyamide and polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, various elastomers such as polyolefin elastomers and polyamide elastomers, and ionomers may be added. Further, additives such as a lubricant, a release agent, a stabilizer, and an ultraviolet absorber, and further, talc and clay based inorganic fillers can be added.

For the addition of the whitening inhibitor, a conventionally known mixing method can be applied. For example, after producing a composition containing a high concentration of anti-whitening agent, diluting it at a predetermined concentration with polyamide pellets containing no anti-whitening agent, melt kneading them, after melt mixing, then injection molding For example, a method of obtaining a molded body by the method is adopted. Further, the polyamide pellets and the whitening inhibitor may be added to the rotating hollow container by adding them.

The thermoplastic gas barrier resin (resin B) of the present invention has good whitening properties immediately after the production of a polyamide molded article, and even after long-term storage under conditions that do not cause whitening or increase whitening. Shows the suppression effect. That is, conditions under which whitening does not occur or whitening does not increase without the addition of a whitening inhibitor, for example, at a temperature of 23
After long-term storage in a 50 ° C., 50% RH atmosphere, exposure to high humidity, contact with water or boiling water, or heating above the glass transition temperature suppresses whitening as in the case immediately after molding.

The multilayer container of the present invention exhibits an effect of suppressing whitening when it is amorphous and non-stretched or amorphous and at a low draw ratio.
The shape of the molded body and the molding method are not limited. Therefore, a molded article obtained by molding the polyamide composition of the present invention exhibits the whitening suppressing effect of the present invention even in a film, a sheet, or a container.

【Example】

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In addition, a method for measuring main characteristics measured in the present invention will be described. (1) Intrinsic viscosity [η] of polyethylene terephthalate:
A mixed solvent of phenol / tetrachloroethane = 6/4 (mass ratio) was used. Measurement temperature 30 ° C. (2) Relative viscosity [ηrel.] Of MX nylon: resin 1 g /
96% sulfuric acid 100 ml, measurement temperature 25 ° C. (3) Haze value: Measured by a color difference meter (model: Z- # 80) manufactured by Nippon Denshoku Industries Co., Ltd. according to ASTM D-1003.

The temperature conditions in the examples and comparative examples are as follows. Multi-layer parison molding (injection molding) Injection cylinder 1a: 270 ° C. Injection cylinder 1b: 260 ° C. Resin flow path in mold: 270 ° C. Mold cooling water: 15 ° C.
It has a diameter of 6.5 mm and a thickness of 4.5 mm. Multilayer container molding (biaxial stretching blow molding) Parison heating temperature: 100 ° C. Blow pressure: 30 kg / cm ² A container obtained by biaxial stretching blow molding of a multilayer parison has a total length of 270 mm, an outer diameter of 80 mmφ, and a volume of 700 ml.

Example 1 Solid-state polymerized polyamide MXD6 (trade name: MX nylon S, manufactured by Mitsubishi Gas Chemical Co., Ltd.) having a relative viscosity of 2.6 pellets 1
Then, 5.0 parts by mass of sodium montanate was added to 00 parts by mass (hereinafter, abbreviated as “parts”), melt-kneaded in an extruder, and then pelletized. The obtained pellet containing sodium montanate was mixed with polyamide MXD6 containing no sodium montanate, and the mixture was mixed with polyamide MXD6.
It adjusted so that 0.2 parts of sodium montanic acid salts might be contained with respect to 0 parts of polyamide MXD6.

Polyamide MXD6 containing 0.2 parts of sodium montanate and polyethylene terephthalate (PE) having an intrinsic viscosity of 0.75 per 100 parts of pellets
T: manufactured by Nihon Unipet Co., Ltd., trade name: RT543C,
Hereinafter, polyethylene terephthalate may be referred to as “PET”) using PET, polyamide MXD6,
Injection was performed in the order of PET to form a 5-layer parison. The polyamide MXD6 was present in an amount of 10 wt% based on the mass of the multilayer parison, and the polyamide MXD6 layer in the multilayer parison extended from the gate to a position having a total length of 90 mm. The obtained multilayer parison was subjected to biaxial stretch blow molding to obtain a 700 ml container. After filling the obtained container with water and capping, 30 ° C.
After storing at / 80% RH for 3 months, the polyamide MXD6 layer was taken out from the low stretch ratio portion (area stretch ratio: 1 to 1.5) of the container, and the haze value was measured. Table 1 shows the results.

Example 2 Unlike Example 1, polyamide MX containing 0.1 part of sodium montanate per 100 parts of pellets
A five-layer parison was formed in the same manner as in Example 1 except that D6 was used. The obtained multilayer parison was subjected to biaxial stretch blow molding to obtain a 700 ml container. The obtained container was filled with water, capped, stored at 30 ° C./80% RH, stored for 3 months, and then subjected to a low stretch ratio portion (area stretch ratio: 1 to 1).
From 1.5), the polyamide MXD6 layer was taken out and the haze value was measured. Table 1 shows the results.

Example 3 Unlike Example 1, polyamide M containing 0.05 parts of sodium montanate per 100 parts of pellets
A 5-layer parison was formed in the same manner as in Example 1 except that XD6 was used. The obtained multilayer parison was subjected to biaxial stretch blow molding to obtain a 700 ml container. The obtained container was filled with water, capped, stored at 30 ° C./80% RH for 3 months, and then subjected to a low stretching ratio portion (area stretching ratio: 1) of the container.
-1.5), the polyamide MXD6 layer was taken out and the haze value was measured. Table 1 shows the results.

Comparative Example 1 Unlike Example 1, a five-layer parison was formed in the same manner as in Example 1 except that the solid-state polymerized polyamide MXD6 having a relative viscosity of 2.6 was used without adding any additives. The obtained multilayer parison was subjected to biaxial stretch blow molding to obtain a 700 ml container. After filling the obtained container with water and capping,
After storing at 30 ° C./80% RH for 3 months, the polyamide MXD6 layer was taken out from the low stretch ratio portion (area stretch ratio: 1 to 1.5) of the container, and the haze value was measured. Table 1 shows the results.

Example 4 Solid phase polymerized polyamide MXD6 (trade name: # 6007, manufactured by Mitsubishi Gas Chemical Co., Ltd.) having a relative viscosity of 2.6, pellets 100
Then, 5.0 parts of ethylenebisstearylamide (trade name: Alflow H-50T, manufactured by NOF CORPORATION) was added to the mixture, melt-kneaded in an extruder, and then pelletized. Polyamide M containing no ethylenebisstearylamide
XD6 was mixed with the obtained ethylenebisstearylamide-containing pellet, and 100 parts of polyamide MXD was mixed.
6 was adjusted to contain 0.2 parts of ethylenebisstearylamide.

Polyamide MXD containing 0.2 parts of ethylenebisstearylamide per 100 parts of pellets
6. PET with intrinsic viscosity of 0.75 (Nihon Unipet Co., Ltd.)
(Trade name: RT543C), PET, polyamide MXD6, and PET were injected in this order to form a five-layer parison. The polyamide MXD6 is present in an amount of 10 wt% based on the weight of the multilayer parison, and the polyamide MXD in the multilayer parison is present.
The six layers extended from the gate to a position having a total length of 90 mm. The obtained multilayer parison is subjected to biaxial stretch blow molding to obtain
A 00 ml container was obtained. The obtained container was filled with water, capped, stored at 40 ° C./80% RH, stored for 6 months, and then subjected to a low stretch ratio portion (area stretch ratio: 1-1.
From 5), the polyamide MXD6 layer was taken out and the haze value was measured. Table 2 shows the results.

Example 5 Unlike Example 4, a 5-layer parison was formed in the same manner as in Example 4 except that polyamide MXD6 containing 0.05 part of ethylenebisstearylamide was used per 100 parts of pellets. . The obtained multilayer parison was subjected to biaxial stretch blow molding to obtain a 700 ml container. After filling the obtained container with water and capping, store at 40 ° C./80% RH.
After storage for 6 months, the polyamide MXD6 layer was taken out from the low stretch ratio portion (area stretch ratio: 1 to 1.5) of the container, and the haze value was measured. Table 2 shows the results.

Comparative Example 2 Unlike Example 4, a 5-layer parison was formed in the same manner as in Example 3, except that the solid-state polymerized polyamide MXD6 having a relative viscosity of 2.6 was used without adding any additives. The obtained multilayer parison was subjected to biaxial stretch blow molding to obtain a 700 ml container. After filling the obtained container with water and capping,
After storage at 40 ° C./80% RH for 6 months, the polyamide MXD6 layer was taken out from the low stretch ratio portion (area stretch ratio: 1 to 1.5) of the container, and the haze value was measured. Table 2 shows the results.

Example 6 A five-layer parison was formed in the same manner as in Example 4. The obtained multilayer parison was subjected to biaxial stretch blow molding to obtain a 700 ml container. The obtained container is filled with an aqueous ethanol solution (an aqueous solution containing 5% by volume of ethanol; the same applies hereinafter), capped, stored at 40 ° C./80% RH, stored for 6 months, and then subjected to a low stretch ratio portion (area) of the container. Stretching ratio: 1-1.
From 5), the polyamide MXD6 layer was taken out and the haze value was measured. Table 3 shows the results.

Comparative Example 3 Unlike Example 6, a 5-layer parison was formed in the same manner as in Example 4, except that the solid-state polymerized polyamide MXD6 having a relative viscosity of 2.6 was used without adding any additives. The obtained multilayer parison was subjected to biaxial stretch blow molding to obtain a 700 ml container. The obtained container was filled with an aqueous ethanol solution, capped, stored at 40 ° C./80% RH, and stored for 6 months.
From 1.5), the polyamide MXD6 layer was taken out and the haze value was measured. Table 3 shows the results.

Table 1 Example 1 Example 2 Example 3 Comparative Example 1 Materials used Polyamide MXD6 MXD6 MXD6 MXD6 Fatty acid metal salt MoNa ^* MoNa MoNa MoNa Compounding ratio (parts by mass) Polyamide 100 100 100 100 Fatty acid metal salt 0.20 .1 0.05-Contents Water Water Water Water Storage conditions Conditions 30 ℃ / 80% RH 30 ℃ / 80% RH 30 ℃ / 80% RH 30 ℃ / 80% RH Period 3 months 3 months 3 months 3 months Cloudiness (%) 21.7 24.9 25.5 47.3 * In Table 1, MoNa indicates sodium montanate.

Table 2 Example 4 Example 5 Comparative Example 2 Materials used Polyamide MXD6 MXD6 MXD6 Diester compound EBS EBS-Compounding ratio (parts by mass) Polyamide 100 100 100 Diester compound 0.2 0.05-Contents Water Water Water Storage Conditions Conditions 40 ° C / 80% RH 40 ° C / 80% RH 40 ° C / 80% RH Duration 6 months 6 months 6 months Haze value (%) 7.6 8.4 41.2 * In Table 2, EBS is ethylene. 2 shows bisstearylamide.

Table 3 Example 6 Comparative Example 3 Materials used Polyamide MXD6 MXD6 diester compound EBS-Compounding ratio (parts by mass)-Polyamide 100 100 Diester compound 0.2-Contents 5% aqueous ethanol solution 5% aqueous ethanol solution Storage conditions Conditions 40 ° C / 80% RH 40 ° C / 80% RH Period 6 months 6 months Haze (%) 11.6 44.6 * In Table 3, EBS indicates ethylenebisstearylamide.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B29C 49/22 B29K 67:00 B29K 67:00 77:00 77:00 105: 32 105: 32 B29L 9:00 B29L 9:00 31:56 31:56 B65D 1/00 BF term (reference) 3E033 BA17 BA18 BA21 BB04 BB05 BB08 CA16 CA18 FA02 FA03 4F100 AH02C AH03C AK41A AK41B AK42 AK46C BA10A BA10B CA30C EH362B16JB GB16H JD03C JN01 4F208 AA24 AA29 AB01 AG03 AH55 LA04 LB01 LB22 LG06 LG28 4J002 CL031 EG026 EG036 EG046 FD026 GF00 GG01

Claims (10)

[Claims] 1. A resin constituting an outermost layer and an innermost layer is a thermoplastic polyester resin (resin A), and a resin constituting at least one intermediate layer between the outermost layer and the innermost layer is a thermoplastic gas barrier resin. (Resin B), wherein the thermoplastic gas barrier resin (resin B) melts a diamine component containing at least 70 mol% of metaxylylenediamine and a dicarboxylic acid component containing at least 70 mol% of adipic acid. A resin obtained by adding 0.005 to 1.0 parts by mass of an additive (whitening inhibitor) having a function of preventing whitening of the polyamide to 100 parts by mass of the polyamide obtained by polymerization. Multi-layer container. 2. A resin constituting an outermost layer and an innermost layer is made of a thermoplastic polyester resin (resin A), and a resin constituting an intermediate layer located between the outermost layer and the innermost layer is a thermoplastic gas barrier resin. A three-layer container made of (resin B),
And a thermoplastic gas barrier resin (resin B) constituting the intermediate layer is disposed from the resin injection port side located at the bottom of the container to the vicinity of a plug portion facing the injection port side. A multilayer container as described. 3. The resin constituting the outermost layer, the innermost layer and the central layer is made of a thermoplastic polyester resin (resin A), and constitutes the outermost layer and the central layer and the intermediate layer located between the innermost layer and the central layer. The resin is a five-layer container made of a thermoplastic gas barrier resin (resin B), and the thermoplastic gas barrier resin (resin B) constituting the intermediate layer is injected from the resin inlet side located at the bottom of the container. The multilayer container according to claim 1, wherein the container is a five-layer container arranged up to the vicinity of a plug portion facing the inlet side. 4. A polyamide obtained by melt-polymerizing a diamine component containing at least 70 mol% of meta-xylylenediamine and a dicarboxylic acid component containing at least 70 mol% of adipic acid,
The multilayer container according to any one of claims 1 to 3, wherein the multilayer container is a solid-phase-polymerized polyamide obtained by melt-polymerizing a diamine component and a dicarboxylic acid component and then performing solid-phase polymerization. 5. Relative viscosity of solid phase polymerized polyamide (1 g of polyamide resin is dissolved in 100 ml of 96% sulfuric acid aqueous solution,
The multilayer container according to claim 4, wherein the value (measured at 25 ° C) is 2.3 to 4.2. 6. The multilayer container according to claim 1, wherein the whitening inhibitor is at least one fatty acid metal salt selected from fatty acid metal salts having 18 to 50 carbon atoms. 7. The multilayer container according to claim 1, wherein the whitening inhibitor is at least one selected from diamide compounds or diester compounds obtained from fatty acids having 8 to 30 carbon atoms and diamines or diols having 2 to 10 carbon atoms. . 8. The multilayer container according to claim 1, wherein the multilayer container is a transparent gas barrier multilayer container obtained by an injection molding method. 9. The multilayer container according to claim 1, wherein the multilayer container is a precursor of a transparent gas barrier multilayer container obtained by an injection molding method. 10. The multilayer container according to claim 1, wherein the precursor of the transparent gas barrier multilayer container obtained by the injection molding method is further obtained by biaxial stretch blow molding.